I don't feel betrayed or let down by the union. My representatives had the mandate to negotiate with the company on a wide range of issues from the moment I elected them, or in my case as with most union members, from the moment I couldn't be bothered to go to the meeting and instead let those who did decide who should represent me.
Of course nobody wants this proposal but we live in the real world and sometimes the nasty world breaks into our idyllic existence. When it does I expect my union representatives to do the best they can and I've no reason to believe they haven't in this case. You can believe all the conspiracy theories or you can trust your representatives. If you don't trust your representatives why did you elect them in the first place ?